Projectile-fuse time-train ring.



E. GATHMANN.

PROJECTILE FUSE TIME TRAIN RING.

APPLICATION mm AUG-311M917.

EG. 1' I WI TNESS MMWW Patented Apr. 29, 1919.

' lel walls Em GATHKANN, OI BALTIMORE, MARYLAND.

PBOJ'ECTILE-FUSE TIME-TRAIN RING.

Specification of Letters Patent.

Patented Apr. 29,1919.

Application filed August 30, 1917. Serial No. 188,934.

To all whom it may concern:

Be it known that I EMIL GATHMANN, a citizen of the United States, residing at Baltimore, State of Maryland, have invented a new and useful Improvement in Pro-' j ectile-Fuse Time-Train Rings, of which the following is a specification.

This invention relates to an improvement in projectile-fuse time-train rings.

In the time-train rings for dial type fuses, mostly used heretofore, it has been customary to ovide powder grooves having paralthe grooves being open to the rear of the rin or toward the body of the projectile. he parallel side walls of the grooves are also parallel with the longitudinal axis of the projectile fuse in the old construction. Tests have recently been made with converging side walls of theooves, and I am aware that a patent has con granted for this converging construction of side walls.

The powder composition of the fuse time ring is inserted in the groove under very heavy pressure per square inchof surface of groove, and it is desirable that the density and hardness of the powder train be as nearly homogeneous throughout all the portions of groove as possible. The type of groove heretofore used has hada ratio of depth approximately 1.5 to width=1.00 or in other words the groove was approximately one and one-half times as deep as wide. In the present artillery practice of high velocity projectiles great accuracy is essential in the uniformity of burning of time train. The necessity of greater uniformity in thehardness and density of the powder composition pressed in the powder groove is thus-evident, as it is well known to those skilled in the art that density and hardness are most important factors in the ignition, inflammation and combustion of all powder products. I have found by ex periment that the density and hardness can be, made more homogeneous, and correspondingly the rate of burning more uniform if the groove is constructed so that the depth of same is approximately equal to the width, or even less than the latter.

' As before stated, the powder composition is forced in the time train groove under heavy pressure. In the usual type of groove with parallel side walls it is however held within the groove only by adhesion of .the train composition with the train ring maverted 'terial, as the parallel side walls of groove are also parallel with the major axis of projectile and fuse. The side walls defining the groove have thus, as used heretofore, always been constructed deeper than their width, so

as to present considerable surface to adheposition in the groove.

With these and other objects not specifically mentioned in view, the invention consists in certain parts and constructions which will be hereafter fully described and then specifically set forth in the claims hereunto a pended.

In t e accompanying drawings, which form a part of this specification, and in which like characters of reference indicate the same or like parts, Figure 1 is an inlan view of a pro ectile-fuse timetrain ring constructed in accordance with the invention; Fig. 2 is a cross-sectional view taken on line 2-2 of Fig. 1; and Fig. 2 is an enlarged fragmentary cross sectional view of a preferred form of groove. In carrying the invention into effect there is provided a projectile-fuse time-train ring provided with a groove of approximately uniform depth (D) and width (W) with approximatel parallel side walls and preferably roun ed at the bottom, and with means other than adhesion and undercut side walls for resisting displacement and, disintegration of the powder composition during gun fire and projectile acceleration as well as during the various machinin manufacturing operations 'in assembly of the fuse.

In the preferred construction as shown in the accompanying drawings, the ring is provided with a powder composition groove and approximately parallel side walls inclining rearwardly and inwardly with reference to and ' on loading and pressing of thepowder com-,

the major axis AA of rojectile and fuse.

structure as shown an descri not restricted to the recise lglgtlails of the Referrin to the drawings, 3 indicates a projectile use-time-traln ring generally f a well known character, but provided with a powder composition groove 4, havin a 2*. As before stated, it is most desirable that the powder composition be homogeneous and of uniform density and hardness and inthe ring groove heretofore ordinarlly of greater depth than width, this is difiicult of attainment even under very high loading pres sures, also, as the deeper the oove, the more diflicult to obtain uniform ensity and hardness. Adhesion only, tends to keep the powder composition in the groove, and the rin being deep, relative to its width, 1t is d cult to obtain a train of powder of a homogeneous uniform density and hardness, which density and hardness are most important factors in the time of burnin of the fuse, as is well known to those familiar with the art. In the present device the width W and depth D, as shown on Figs. 2 and 2", are approximately of the same dimension, and the actual surface which governs the size of loading die is enlarged as shown at S, thus allowing of a free unimpeded flow of powder com osition during the pressing operation, an consequentl thus obtaining a greater uniformity in hard ness and density of the powder composition train. These last. named results are not readily obtainable in the lately advocated undercut groove construction which is described in a recent U. S. patent. As the loading pressure on the powder composition when pressed within the groove is far eater than any possible pressure due to Inertia of composition' or set back due tofiring of projectile from gun, and as the walls rigidly support the same against' bodily movement, it will be readily understood that disintegration or breaking up of the" train of powder composition cannot occur. It should be noted that the free face of the powder composition, when the fuse is assembled, is pressed a%ainst a washer of felt or the like material ttedto a platform either on the body of the fuse or on a time train rin mounted behind the one here shown. her forms of grooves not shown but capable of 'efl'ectmg the same results may of course be used in place of the. preferred form shown in the drawings.

What-is claimed is: 4

1. A projectile-fuse time-train ring provided with a powder composition groove open to the rear end and havin approximately parallel retaining sidd wa s, none of the elements of the said side walls being perallel with the longitudinal axis of the 2. A projectile-fuse time-train ring provided with a powder composition grooveopen to the rear end and having approximately parallel retaining side walls, and a rounded bottom, none of the elements of the said side walls being parallel with the longitudinal axis of the projectile-fuse. 1

3. A projectile-fuse time-train ring pro-, .vlded .w1th a powder composition groove open to the rear end and having side walls which are portions of co-axial cones having those adjacent elements that. lie in the same axlilal plane approximately parallel to each ot er.

4. A projectile-fuse time-train ring pro-' vided with a powderj com sition" groove open to the rear end and aving approximately parallel sidewalls, none of the elements of the side walls being parallel with the longitudinal axis of the fuse, the open EMILGATHMANNZ. 

